This invention relates generally to an improved vehicle lamp assembly, and particularly to an improved anti-rotational lamp construction for an automotive vehicle lamp assembly. Automotive vehicles, and particularly commercial vehicles, are subjected to recurrent road shocks in traveling over the highway. These road shocks, transmitted through the frame of the vehicle, affect the relatively fragile filaments of the lamp bulbs in the marker, signalling and driving lamps of the vehicle, so that such bulbs frequently break or become inoperative due to the road shocks. Thus, the lamp bulbs must be replaced at rather frequent intervals. With some types of lamps, such replacement is difficult for the driver of the vehicle to perform on the road. In addition, the driver is often unaware that the lamp bulbs on his vehicle have broken, or the lamps are inoperative, as his opportunity for observing the lamp condition occurs only when the vehicle is stopped, as at a rest area or during a change of drivers.
In order to facilitate replacement of a damaged lamp, the industry has adopted sealed lamp housings which are replaced instead of the bulbs. In some cases it is desirable to have a lamp housing which can be installed in the vehicle without requiring screws or other fastening means. Rubber grommets for compressively engaging the sealed housing have been adopted for some applications, but under severe road vibration may cause rotation of the grommet and/or housing relative to the vehicle wall. This rotation subjects the electrical lead wires to abuse and increases the likelihood of damage.
Various means have been proposed to overcome this rotation of the automotive vehicle lamp housing. It has been proposed to provide radial ribs on an elastomeric mounting grommet force-fit into a wall opening and a curved lamp housing compressively retained therein. This construction has reduced rotation of the lamp assembly to some extent. However, in actual use undesirable rotation occurs and the grommet must be installed with additional means such as a screw to prevent rotation of the grommet. This has not prevented rotation of the lamp housing within the grommet and this arrangement has proved less than fully satisfactory. Accordingly, it is desirable to provide an anti-rotational lamp construction which will further reduce rotation of an automotive vehicle lamp and which, in addition protects the lead wires from strain. It is also desirable to provide an improved anti-rotational lamp construction which may be more easily constructed, readily assembled and installed in a vehicle than those suggested in the prior art.